The present invention is directed to an overflow system for sinks, lavatories or the like which have an overflow opening and, in particular, to an overflow system which interconnects the overflow opening and the drain opening of a sanitary fixture, especially designed and constructed to be encapsulated in a molded plastic material that is bonded to the back surface of the sanitary fixture.
Sanitary fixtures such as sinks, basins, lavatories and the like are generally provided with a drain opening located at the bottom of the bowl and an overflow opening located in a side wall of the bowl proximate the top rim thereof. A conduit or tube is generally provided to interconnect the drain opening and the overflow opening such that when water in the bowl reaches the level of the overflow opening, the water will flow therethrough, into the conduit and into the drain coupled to the drain opening. This prevents water from flowing over the top of the bowl. The overflow assembly is generally formed as an integral passage in china and porcelain fixtures. Alternatively, in enameled steel fixtures, the overflow assembly is separately formed from a steel member and is generally welded to the fixture before the enamelling process takes place.
Recently, it has been proposed to provide a steel or enameled steel fixture having a plastic material bonded to the underside thereof. For example, U.S. Pat. No. 4,664,982 discloses a multi-layer composite structure such as a plastic backed enamel steel sanitary fixture having high impact and thermal shock resistance. The composite structure is formed by bonding a layer of reinforced plastic to the underside of the fixture to form a laminated structure. Thus, a product is produced with a finished layer that is resistant to delamination when subjected to relatively high impact or sudden temperature change applied directly to the finished and/or plastic layer surface.
In the past, when steel sanitary fixtures were formed using a process like that disclosed in U.S. Pat. No. 4,664,982, a one piece overflow assembly was constructed to couple the overflow opening to the drain opening. Such overflow assemblies were constructed of a steel conduit formed to fit the curvature of each particular fixture. A steel conduit was required to withstand the high pressures exerted during molding. The first end of the conduit was configured to cover the overflow opening of the basin and the second end was configured to discharge water in the conduit into the drain. Thus, a special preformed steel overflow channel was required for each differently configured fixture. Furthermore, the metal assemblies were required to be welded to the metal basin prior to the molding process.
It is important in providing an overflow system for a sanitary fixture subjected to a molding process that the components be inexpensive to manufacture while being adapted to withstand the pressures exerted during the molding process. It is also preferable that the drain outlet fitting and overflow outlet fitting be formed separately from the conduit so that these elements of the overflow system may be mass produced to fit several sanitary fixtures, and only a separate conduit need be designed to accommodate significant variations in basin design.
Accordingly, it is desired to provide an encapsulated overflow system which meets the criteria set forth above for operative convenient and inexpensive manufacture thereof.